The invention lies in the field of household appliances. The invention relates to a gas burner for cooking areas.
A gas burner is disclosed in European Patent EP 0 415 049 B1. The burner includes a lower part seated on an upper part and in which gas outlet openings for gas flames are formed. Connected centrally to the underside of the lower part is a feed pipe for the feeding of combustion gas and primary air.
Prior art gas burners on the market produce a static flame pattern. The minimum output that can be set is relatively high and is concentrated on small areas in the region of the flames. Such concentration often leads to food burning in a pot that is standing on the gas burner, even when the minimum output is set. The gas flames cannot be made unlimitedly as small as desired, but instead go out below a minimum size, required for maintaining the burning state.
U.S. Pat. No. 2,646,788 discloses a gas burner in which the upper part can rotate on the lower part. An additional drive mechanism is required for the driving of the upper part. French Patent No. FR 1 535 256 A describes a gas burner in which the upper part is mounted in the lower part by a perpendicularly disposed spindle. The upper part is able to rotate on the lower part due to horizontally disposed gas outlet openings. The disadvantages of these solutions are not only very complex constructions, in particular, in the case of the mounting or the drive in the U.S. specification, but also that they aim for a maximum burner output, which is based on a better surface area distribution. Such distribution is not possible with these solutions to minimize the burner output, for example, when keeping food warm.
It is accordingly an object of the invention to provide a gas burner for cooking areas that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that distributes the heat of a gas burner over as large a surface area as possible, in particular, when set to the minimum output. Furthermore, the invention is intended to provide a possible way of further minimizing the smallest possible output of gas burners.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a gas burner for cooking areas, including a lower part, and an upper part having gas repulsion ducts with gas outlet openings for gas flames, the upper part rotatably mounted on the lower part by a compressed-air bearing configured to apply a compressed-air cushion to pneumatically lift the upper part off the lower part for allowing contactless turning of the upper part in relation to the lower part about an axis of rotation, the gas repulsion ducts being formed to drive the upper part in relation to the lower part about the axis of rotation by gas flowing through the gas repulsion ducts at positive pressure.
The gas burner according to the invention has the advantages that it distributes the heat produced by its gas flames under a pot or other utensil more evenly over a larger surface area than the prior art gas burners, in particular, when set to the minimum output (gas burner set to the smallest possible flame size), and that it can be set to a smaller minimum output than prior art gas burners.
The gas burner according to the invention is preferably configured such that, when set to the minimum output, only a very small number of individual gas flames are produced. According to the invention, only one to five individual gas flames are preferably provided. These gas flames are set in rotation at low speed, preferably in the range between 20 and 100 rpm. Such rotation achieves the effect that, because of the reduced number of gas flames, the overall output of the burner is reduced, although the length of the individual flame may well be greater than in the case of prior art gas burners. The rotation has the effect that the heat is evenly distributed under a pot or other utensil that is standing on the gas burner.
In accordance with another feature of the invention, the axis of rotation is a vertical axis of rotation.
In accordance with a further feature of the invention, the gas repulsion ducts are formed to drive the upper part in relation to the lower part in a circumferential direction.
In accordance with an added feature of the invention, the gas repulsion ducts are curved and have side walls pointing in a circumferential direction to be driven by the gas flowing at positive pressure about the axis of rotation.
In accordance with an additional feature of the invention, the gas repulsion ducts are turbine blade-shaped.
In accordance with yet another feature of the invention, the upper part has an outer circumference, the gas repulsion ducts have downstream end portions with gas outlet openings at the outer circumference, and the openings are directed in a circumferential direction and counter to a direction of rotation of the upper part to produce a gas repulsion from emerging gas for driving the upper part about the axis of rotation.
In accordance with yet an added feature of the invention, the gas repulsion ducts open downward toward the lower part, the upper part has lands between the gas repulsion ducts, and the lands are configured to support the upper part on the lower part.
In accordance with yet an additional feature of the invention, the gas repulsion ducts form the compressed-air bearing.
In accordance with again another feature of the invention, the gas repulsion ducts have radially inner, upstream beginnings and downstream ends with gas outlet openings for gas flames, and including a duct disposed in or in a vicinity of the axis of rotation for feeding one of combustion gas and a mixture of combustion gas and air, the duct fluidically connected to the beginnings.
In accordance with again an added feature of the invention, the gas outlet openings are disposed in a horizontal plane, the gas repulsion ducts have downstream outlets disposed in another horizontal plane, the gas repulsion ducts have upstream portions, and including a duct for feeding one of combustion gas and a mixture of combustion gas and air, and another duct for feeding air at a positive pressure with respect to the surroundings, the gas outlet openings being fluidically connected with the duct and the upstream portions being fluidically connected with the another duct.
In accordance with again an additional feature of the invention, there is provided a compressed-air source for feeding air at a pressure above atmospheric pressure to the gas repulsion ducts.
In accordance with a concomitant feature of the invention, the upper part has an increasingly reduced diameter in a downward direction at a region of the gas repulsion ducts, the lower part has a depression having another increasingly reduced diameter in the downward direction matched to the diameter, and the region protrudes into the depression.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a gas burner for cooking areas, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.